Zippo Flame Gulper

[PJW]

This is the first engine of this type I have tried, Woodster was kind enough to send me the plans for this engine that was designed to run using a Zippo lighter. I did in fact make two of these, one to give to a good friend of mine.

[b.lindsey]

That is an interesting design Peter and well done too!!  If possible could you take a picture or two of the valve at both ends of its movement and the arrangement of the port into the cylinder? Also, what type of spring mechanism is there to keep the valve rod against the cam?

Bill

[PJW]

Hi Bill, i will upload the pics soon, these two show the valve & two magnets that hold the lighter in position.

[b.lindsey]

Thanks Peter, that helps already, the earlier pictured didn't show the "leaf spring" that covers the cylinder port so that makes sense now

Bill

[PJW]

I have only one problem with this engine, I cant get the blooming to go!!!! I have tried for a long time, I can get a vacuum & get the flame to be drawn into the engine but I cant get it to run. I has been sat next to my desk laughing at me for months now! I did say to Woodster that I would put it on the forum, but I think I have failed on this one.

[b.lindsey]

Peter, the downside to flame gulpers is that they can be very finiky to get to run. There are generally two things that can cause this. The first is that the piston to cylinder clearance needs to be very close!! You can't have too much friction since they produce very little power, but if the fit is too loose then you loose the vacuum which is what makes it run. You might also check to be sure the "valve" (leaf spring) seals the cylinder as well, the surfaces need to be very smooth.  The other major thing can be timing so you can play around with the cam a bit and see if that gets you any closer to having a runner.

As for the piston fit, if you take the cylinder and seal off the valve opening and then insert the piston (in a vertical orientation), the piston should fall very slowly into the cylinder just from its own weight. Obviously if the valve opening is not sealed (meaning like with your finger) the piston will literally fall into the cylinder. If you can get these two conditions then the piston fit is likely good.

Sorry if you know all this already.

Hope this may help some. Don't give up on it yet, they are really fun to watch once you get them to go!!

Bill

[PJW]

thank you Bill I will have another look at it and come back later!

Peter

[90LX_Notch]

Peter-

That's a neat little engine.

Bill is correct on all counts.  Another way to check the piston fit is if it it makes a "pop" sound when you pull it out of the cylinder.  The piston and cylinder on my Poppin were lapped in with Crest Toothpaste (only thing I had handy) to get the fit right.

It is hard to tell from the picture, but it looks like the cam is about 180* out.  The valve needs to be fully closed at bdc and remain closed on the upward stroke.  Remember that the vacuum of the contracting gas is what draws the piston up for it's "power" stroke.  It is completely opposite of an ic engine.  I made this mistake when I built my Poppin.  Once I got the valve timing right, it ran like a champ.

-Bob

[PJW]

Hi bob, yes the timing is 180 out, I will reset & have another go at starting it, thanks!

Peter

[Woodster]

Hi Peter, Nice job!!
Sorry to hear you're having trouble. I've just had a quick look at the original engine and agree that the valve timing is off. Also, check the distance between the top of the Zippo and the bottom of the port. It should be 4 - 5mm. FYI, My valve is timed about 170 degrees opposite the conrod at BDC, if you know what i mean (Conrod at BDC, Large part of Cam almost opposite, but off by 10 dergees). Also, my valve does not open fully. About 1/2 mm remains covered. Hope this helps

[90LX_Notch]

Very easy to do Peter.  I think that is where most people have trouble with flame gulpers.  It is opposite of how most engines work.

-Bob

[PJW]

Hi Woodster, do you mean 10 degrees before bdc? I have just removed the piston & cylinder and lapped it in a little more, it does not quite slide down under its own weight, but it almost does. next I will double check the valve & timing. your engine seems to belt away, I am no where near that yet

Peter

[Woodster]

Hi Peter.
It doesn't matter whether it's 10 degrees before or after. It should run one way or the other.

[Zephyrin]

It seems that the flame is higher than the cylinder port, then your engine breathes mainly cold air, which is a no-no ! (but it could be a perspective effet on the photograph )
And the links of the valve may induces too much drag, this part must be light and free to move.

[mklotz]

All the above and let me add...

If the cylinder is too cool it will "quench" the incoming hot gas too quickly.  Try preheating the cylinder with the Zippo before you attempt to run it.